Envelope-stuffing device

ABSTRACT

The present invention pertains to the object of substantially increasing the performance of an envelope-stuffing machine. While EP-A-0 504 114 discloses the use of rotating elements for opening the envelopes and for grasping the envelope flaps for this purpose, the present invention suggests that the opening and grasping of the envelopes (20) be performed in one conveying plane (13), and the introduction of the envelope contents (21) be performed in a conveying plane (12) arranged offset in relation thereto at another level, and that a link chain (10) with a plurality of spreading members (9) be provided between them, which is movable at right angles to the conveying planes (12, 13) and keeps the envelopes (20) picked up by the spreading members (9) ready at another point for the introduction of the envelope contents (21) and discharges them.

The present invention pertains to an envelope-stuffing device with astacking device and a pull-off device each for the envelopes and for theenvelope contents, as well as with a device for spreading the envelopesand for introducing the envelope contents into the spread envelope,along with a conveyor for removing the stuffed envelopes.

Prior-art envelope-stuffing machines of this class have a limitedoutput, because the opened envelope pulled off from the stack must bepulled from one side onto a so-called packing pocket, with which theenvelope is also spread at the same time. The envelope contents are thenfed into the packing pocket from the other side and pushed into theenvelope. Consequently, the two processes take place one after anotherand thus limit the maximum efficiency of the envelope-stuffing device.

The task of approximately doubling the stuffing speed has been knownfrom EP-A 0 504 114. The reciprocating movements of different elementsin the prior-art envelope-stuffing machine were believed to be the causeof the impossibility of increasing the output. It is suggested in EP-A 0504 114, instead, that an increase in output be brought about byperforming the opening and the pulling off of the envelopes from thestack by means of rotating elements, which are mounted on a common axis,but are driven differently. However, this disclosure also involves theuse of a packing pocket, onto which the envelope fed in must first bepulled in order to introduce the envelope contents into the envelopefrom the other side.

In contrast, the basic object of the present invention is to bring aboutthe desired increase in output by working with a plurality of packingpockets in such a way that one envelope is pulled! onto one packingpocket and another envelope at another point is stuffed with theenvelope contents at the same time in order to thus substantially reducethe cycle times.

This object is accomplished according to the present invention by thedevice for spreading and keeping ready the envelopes being designed as alink chain equipped with a plurality of spreading members, whoseconveying plane extends at right angles to and between the conveyingplanes for the envelopes and the envelope contents, which are located atdifferent levels, wherein the individual spreading member picks up theopened envelope in one conveying plane during the stopped phase andkeeps the envelope received ready for pushing in the envelope contentsin the other conveying plane.

Consequently, the cycle time is reduced in the subject of the presentinvention by the pulling of the envelope onto the spreading member(packing pocket) taking place simultaneously with the pushing of theenvelope contents into another envelope and by the time needed to feedin or pull off an envelope being used to move the spreading members fromthe envelope pick-up station into the discharge station.

Advantageous embodiments of the present invention are disclosed inclaims 2 through 6. It is advantageous, e.g., according to claim 2 toallow the conveyors for the envelopes and for the envelope contents torevolve continuously and the link chain intermittently. An additionalincrease in output is achieved as a result, because the times forpulling the envelopes onto the spreading member and for stuffing in theenvelope contents and for pulling off the stuffed envelope can befurther reduced.

According to claim 3, it is recommended that the conveyors for theenvelopes and for the envelope contents be allowed to revolve in thetransfer area in the horizontal plane (at levels one on top of another)and the link chain in the vertical direction.

Another subject of the present invention pertains to the special designof the link chain according to claim 4. According to this claim, thelink chain comprises two individual chains, which are arranged at spacedlocations from one another, revolve around mutually parallel axes, andon which the spreading members are arranged in the same plane, directedtoward each other. The envelope fed in can consequently be spread withease during the pulling onto the two spreading members aligned inparallel to one another, which leads to the advantage that a largeramount of envelope contents can be fed in. The spreading members loadedwith the envelope are displaced intermittently into a raised level,which prevents collisions with the gripping tools for the envelopes. Itis therefore advantageous for the individual chain to have at leastfour, but preferably eight spreading members arranged at equally spacedlocations from one another.

To reduce the cycle times, provisions are made according to claim 6 ofthe present invention for the conveyor for the envelopes to have aplurality of grippers arranged at equally spaced locations from oneanother for grasping the flaps of the envelopes, to take over theenvelopes from a stack pull-off device in its lower strand, and totransfer the envelopes to the spreading members in its upper strand.

Details of the present invention are shown in the drawings schematicallyand as examples. In the drawings,

FIG. 1 shows a schematic side view of an envelope-stuffing machine,

FIG. 2 shows an enlarged side view of a spreading device for envelopesdesignated by (7) in FIG. 1,

FIG. 3 shows a top view of the spreading device according to arrow A inFIG. 2,

FIG. 4 shows a front view of the spreading device according to arrow Bin FIG. 2,

FIG. 5 shows an enlarged side view of a gripper designated by (17) inFIG. 1, and

FIG. 6 shows an enlarged side view of the device for introducing theenvelope contents into envelopes, which is designated by (8) in FIG. 1.

The exemplary embodiment shown in FIG. 1 is based on the fact that theenvelopes (20) are pulled off from a stack (1), an intermediate stack,or a defined position by means of a pull-off device (2) and aretransferred to a conveyor (5). This conveyor (5) is designed, e.g., as arevolving toothed belt, is provided with a plurality of grippers (17),and revolves around horizontal axes. It is essential for this conveyor(5) to form with its upper strand (19) a conveying plane (13) whichextends horizontally. The lower strand (18) of this conveyor (5)extends, in contrast, in the pull-off plane of the pull-off device (2).

The conveying plane (12) of the conveyor (6) for envelope contents (21)is located at a marked vertical distance from the conveying plane (13)of the conveyor (5) for envelopes (20). These envelope contents (21) arelocated in one or more stacks (3), with which pull-off devices (4) areassociated. It is possible as a result to combine an envelope contents(21) comprising a plurality of sheets on the conveyor (6) in order tofeed this plurality of sheets as one pack into the envelope (20).However, it is conceivable that a plurality of stacks (3) are arrangedfor the same envelope contents (21) one behind the other to bring theenvelope contents pulled off alternatingly onto the conveyor (6). Thecycle times can be reduced as a result if the conveying capacity of theconveyor (6) for envelope contents is greater than the feeding capacityof the individual pull-off device (4).

The conveying plane (12) of the conveyor (6) for envelope contents (21)extends in parallel to the conveying plane (13) of the conveyor (5) forenvelopes (20) and is located at a laterally markedly spaced locationfrom this. This space between the two conveying planes (12, 13) isfilled by a spreading device (7) for envelopes (20), which in turncomprises a link chain (10) which has a plurality of spreading members(9) (packing pockets), as is specifically shown in FIGS. 2 through 4.The link chain (10) revolves in a vertical conveying plane according toarrow 11 and is intended to bring the spreading members (9) into therange of action of the grippers (17) of the conveyor (5) for envelopesalong the conveying plane (13) and then to raise them into the level ofthe conveying plane (12) of the conveyor (6) for envelope contents (21).Since the link chain (10) has a plurality of spreading members (9)located at equally spaced locations one behind the other, the openedenvelope is fed into the spreading member (9) located in the conveyingplane (13), while another spreading member (9) located in the conveyingplane (12) keeps the spread envelope (20) contained sic--probable typefor "obtained"--Tr. Ed.! ready for pushing in the envelope contents (21)and for pulling off the stuffed envelope.

Consequently, the cycle times of the envelope-stuffing machine accordingto the present invention can be substantially reduced, because it isrecommended that the conveyors (5 and 6) be allowed to revolvecontinuously, whereas the link chain (10) with the spreading members (9)is driven in an intermittent manner.

The link chain (10) with the spreading members (9) fastened to it isshown on a larger scale in the example shown in FIG. 2. While the lowerspreading member (9) has not yet picked up any envelope,. it isrecognized at the middle and upper spreading members (9) how theenvelope (20) has been pushed, with its envelope flap (23) in front,onto the spreading members (9).

This pull-off process is especially dearly visible in FIG. 3. Thespreading members (9), which are always located in an inner position,.extend into the edge area of the opened envelope (20) and hold same andalso form a spreading of the envelope (20). The envelopes (20) arebrought in this position to the level of the conveying plane (12) forthe envelope contents (21).

The example in FIG. 4 shows that the link chain (10) is divided into twoindividual chains (14, 15) which revolve around parallel horizontal axes(16) at spaced locations from one another and may consist of, e.g.,toothed belts. The spreading members (9) of the two individual chains(14, 15) are parallel to each other when they are in the conveyingplanes (12) and (13). An opened envelope is consequently pulled over twomutually opposite spreading members (9). The individual spreading member(9) therefore needs only to penetrate into the envelope edge associatedwith it, as a result of which maximum spreading is achieved, which makesit also possible to introduce a larger amount of envelope contents (21).

FIG. 5 shows on a larger scale how the envelope (20), pulled off andopened, is grasped by the gripper (17) of the envelope conveyor (5) andis carried along the lower strand (18) of this envelope conveyor (5) inthe direction of the arrow.

The device for introducing the envelope contents (21) into envelopes(20), which is shown in FIG. 6 on a larger scale, comprises a conveyor(25), which is provided with carriers (24), and whose carriers (24)grasp the envelope contents (21) located on the conveying plane (12) onthe rear side and push them into the envelopes (20) being kept ready.

LIST OF REFERENCE NUMBERS

1 Envelope (stack of envelopes) kept ready

2 Pull-off device for envelopes

3 Stack for envelope contents

4 Pull-off device for envelope contents

5 Conveyor for envelopes

6 Conveyor for envelope contents

7 Spreading device for envelopes

8 Device for introducing the envelope contents into envelopes

9 Spreading member

10 Link chain

11 Conveying plane of the link chain

12 Conveying plane of the conveyor for envelope contents

13 Conveying plane of the conveyor for envelopes

14 Individual chain

15 Individual chain

16 Parallel axes

17 Gripper

18 Lower strand

19 Upper strand

20 Envelope

21 Envelope contents

22 Conveyor for removing stuffed envelopes

23 Envelope flap

24 Carrier

25 Conveyor

I claim:
 1. An envelope stuffing device, comprising:a conveyor forremoving stuffed envelopes; envelope contents stacking and pull-offmeans for stacking and pulling off envelope contents, said envelopecontents stacking and pull-off means including an envelope conveyor withan envelope conveying plane; envelope stacking and pull-off means forstacking and pulling-off envelopes, said envelope stacking and pull-offmeans including an envelope conveyor with an envelope conveying plane;spreading means for spreading open each envelope and positioning eachenvelope for introducing the envelope contents, said spreading openmeans including a revolving pair of link chains provided with aplurality of spreading members, said pair of link chains being disposedbetween an envelope conveying plane adjacent to said envelope pull-offmeans and an envelope contents conveying plane adjacent to said envelopecontents pull-off means, said envelope conveying plane being located ata different level from said envelope contents conveying plane, said linkchains being disposed at right angles to said envelope conveying planeand said envelope contents conveying plane; and intermittent drive meansfor driving said link chains intermittently whereby said spreadingmembers of said pair of link chains pick-up envelopes in said envelopeconveying plane during a stopped phase of said link chains, convey saidpicked-up envelope to said envelope contents conveying plane and pushsaid envelope contents into said envelope at said envelope conveyingplane.
 2. An envelope stuffing device according to claim 1, wherein saidenvelope conveyor and said envelope contents conveyor are continuousconveyors revolving continuously.
 3. An envelope stuffing deviceaccording to claim 2, wherein said envelope conveyor and said envelopecontents conveyor provide transportation in a horizontal transfer planeand said link chains provide transportation in a vertical direction. 4.An envelope stuffing device according to claim 1, wherein said pair oflink chains comprise two individual chains, arranged at spaced locationsfrom one another, said chains revolving around mutually parallel axes,said spreading members being arranged on said individual chains in thesame plane, said spreading members of one of said two individual chainsbeing directed toward the spreading members of the other of said twoindividual chains.
 5. An envelope stuffing device according to claim 1,wherein each of said individual chains has at least four spreadingmembers arranged at equally spaced locations.
 6. An envelope stuffingdevice according to claim 1, wherein each of said individual chains haseight spreading members arranged at equally spaced locations.
 7. Anenvelope stuffing device according to claims 2, wherein said envelopeconveyor includes a plurality of grippers arranged at equally spacedlocations, each of said grippers for grasping an envelope flap andmoving an envelope from said envelope stacking and pull-off means ofsaid envelope conveying plane to said supporting members, said spreadingmembers being located above said envelope conveying plane.